Subtract 20/21 from 15/56
15/56 - 20/21 is -115/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 56 × 3 = 168,
15/56 = 15 × 3/56 × 3 = 45/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
20/21 = 20 × 8/21 × 8 = 160/168 - Subtract the two like fractions:
45/168 - 160/168 = 45 - 160/168 = -115/168
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